I. Field of the Invention
The present invention is directed to a dropper bottle assembly used to dispense liquids.
II. Description of the Prior Art
Dropper bottle assemblies are used to dispense a variety of liquids, typically one drop at a time. For example, dropper bottle assemblies are used for the dispensing of liquid reagents in laboratories, dispensing eye medication, dispensing ear medication, or in any other environment where dispensing of a liquid in controlled drop increments is desired.
One typical prior art dropper bottle assembly comprises a plastic bottle, a nozzle or spout section which is press fit onto the bottle and a cap which is threaded onto the bottle. Liquid is dispensed one drop at a time by squeezing the bottle so as to force liquid out the end or tip of the nozzle. Due to the construction of the bottle assembly, leakage is a problem during dispensing. An additional problem with this type bottle construction is that filling of the bottle by the liquid manufacturer requires a two-step assembly process. After the bottle is filled with the appropriate liquid to be dispensed, the nozzle must first be press fit onto the bottle and the cap then threaded onto the bottle. This two-step assembly process typically requires expensive capping equipment.
Another typical prior art dispensing bottle assembly comprises a plastic bottle, a dispensing plastic nozzle threaded onto the neck of the bottle, and a cap threaded onto the nozzle. With this type of bottle assembly, the cap must thread down over the nozzle far enough for the top inner surface of the cap to engage the top of the dropper spout in order to seal the spout against leakage. Mismatch in parts, and over or under tightening of the cap, may result in an inadequate seal and leakage.
Additionally, a serious problem with both types of prior art dropper bottle assemblies is contamination of the liquid to be dispensed. In many instances, such as in laboratories and research centers, a variety of different liquid reagents may be used together. Typically, these reagents are quite expensive and extremely sensitive to contamination. The caps of the bottles are typically taken completely off and placed on a bench during use and are later returned to their respective bottles. The possibility exists that the cap will be replaced on the wrong bottle, thus resulting in cross contamination between different reagents. If recognized, these reagents should be discarded. However, if the user fails to recognize this cross contamination, the continued use of such reagents could result in faulty test results. In addition to cross contamination, great care must be taken to avoid contamination of the cap or the nozzle that may be caused by the fingers of the user or by the surface upon which the cap is placed. In some instances, the user will attempt to hold the cap in his hand while also holding the bottle. This makes dispensing of a liquid cumbersome and presents the possibility of dropping the cap which can also result in contamination.